1. Field of the Invention
The invention relates to a substrate structure. Particularly, the invention relates to a substrate structure having a heat dissipating effect.
2. Description of Related Art
Light-emitting diodes (LEDs) have been widely used as indicators or light sources in home appliances and various equipments due to its advantages of long service life, small size, high shock resistance, low heat generation and low power consumption, etc. In recent years, the LEDs are developed to have a high power, and application domains thereof have been extended to road lighting, large outdoor billboards, traffic lights, and related fields. In the future, the LED may even become a main illumination light source having both of a power saving function and an environmental protection function.
Generally, when a high power LED chip emits light with a high brightness, a large amount of heat is generated. If the heat energy cannot be dissipated and is continuously accumulated within the LED chip, a temperature of the LED chip is continuously increased. In this way, the brightness and the service life of the LED chip are probably decreased due to overheat, which may even cause a permanent damage. Moreover, in a high density and multi-chip package structure, since the LED chips are arranged in an array, the heat generated by the LED chips at a central area of the whole array is hard to be dissipated compared to the heat generated at a peripheral area of the whole array. Namely, the heat generated by the LEDs is gathered at a central position of the multi-chip package structure. In this way, the service life of the LED chips at the central area is liable to be shorter than the service life of the LED chips at the peripheral area, which may influence reliability of the whole multi-chip package structure.